1. Field of the Disclosure
The disclosure relates generally to valves used to regulate fluid and/or gas pressure in a system and more particularly to valves employing a ball valve to regulate fluid and/or gas pressures.
2. Statement of the Prior Art
Current miniature pressure regulating valves used for devices, particularly medical devices such as inhalers, often go through long periods of little or no use (possibly years) during which the valve is not actuated. Long periods of inactivity allow environmental conditions and contained fluids and gases to erode and degrade valve components. Yet, due to the often criticality of use, the valve is expected to work properly in an instant when activated.
One gas, in particular, often used in medical devices as a propulsion source, or as a medicament, can cause severe component erosion and functional degradation if left unused over long periods of time. CO2 can interact with environmental molecules to form acids and other material degrading substances when left in a contained, pressurized condition. Leaks over time, however small, result in equipment failure or poor performance. Thus, there is a need to minimize the number of components incorporated into a pressure regulator valve to reduce possible points of equipment degradation and/or failure.
Problems associated with long term non-use are further exacerbated by the need to separate a high pressure gas or fluid source from a low pressure delivery source akin to a regulator in scuba gear, or to a medical inhaler used to administer a variety of medicaments. The transition from a high pressure source to a low pressure source has to be consistent, stable and repeatable, and the resistance needed to activate a regulator valve has to be consistent also. The valve has to transition from a closed to an open configuration in a very short distance of travel to maximize the speed of fluid and/or gas delivery without compromising the precision of the quantity administered.
Further problems arise when valves used in the recited manner are required to reduce relatively high fluid or gas pressures to relatively very low pressures. Many of the prior art valves used for this purpose can only handle relatively small reductions in pressure. In addition, many such valves have problems with valve seats. It is difficult to obtain the geometries and finishes necessary to maintain a good valve seat when addressing large reductions in pressure. A yet further problem is to achieve these results with durability and longevity of components.
What is described herein solves these problems by using a stem-actuated ball valve in conjunction with a dual-purpose o-ring seal to provide a valve seat for the ball valve and to consistently and completely seal off the high pressure source from the low pressure delivery source over long periods of time. The disclosure also provides an apparatus to reduce relatively high pressures to much lower pressures in a quick, precise and repeatable manner.